Environmental Engineering Reference
In-Depth Information
10
−
5
10
−
6
10
−
7
k
s
= 1
×
10
−
7
- 3
×
10
−
6
10
−
8
10
−
9
Gardner (1958a) fit
Monitored suction,
H
= 100 mm
Monitored suction,
H
= 300 mm
Monitored suction,
H
= 600 mm
Monitored suction,
H
= 800 mm
Inferred suction,
H
= 100 mm
Inferred suction,
H
= 300 mm
Inferred suction,
H
= 600 mm
Inferred suction,
H
= 800 mm
10
−
10
λ
=
−
2.06
10
−
11
10
−
12
10
−
13
0.01
0.1
1
10
100
1000
10,000
100,000
Soil suction,
ψ
(kPa)
Figure 7.50
Calculated unsaturated permeability functions for ML soil (after Li et al., 2009).
10
−
5
10
−
6
10
−
7
10
−
7
- 4
10
−
6
k
s
= 2
×
×
10
−
8
10
−
9
10
−
10
Gardner (1958a) fit
Monitored suction,
H
= 100 mm
Monitored suction,
H
= 300 mm
Monitored suction,
H
= 600 mm
Inferred suction,
H
= 100 mm
Inferred suction,
H
= 300 mm
Inferred suction,
H
= 600 mm
λ
=
−
1.84
10
−
11
10
−
12
10
−
13
0.01
0.1
1
10
100
1000
10,000
100,000
Soil suction,
ψ
(kPa)
Figure 7.51
Calculated unsaturated permeability functions for SC with gravel (after Li et al.,
2009).
The SWCCs can also be used in Eq. 7.80 to extend the
suction range. The soil suctions can be estimated from the
SWCCs (see Fig. 7.44) through use of the monitored water
contents. The permeability functions can then be calculated
over a much wider suction range, as shown in Figs. 7.49 to
7.51 (i.e., see the solid symbols).
There is a distinct overlap between the permeability
function computed from the suction measurements and that
from inferred suctions taken from the SWCC. The perme-
ability functions from the measurements at section heights
of 100, 300, and 600mm tend to form a loglinear band.
The upper values tend to be about 5-10 times higher than
that of the lower values at the same suction. The Gardner
(1958a) equation can be used to best fit the calculated data
on the CL sand using a saturated coefficient of permeabi-
lity of 3
.
0
10
−
7
m/s. The laboratory-measured saturated
×
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